The effect of template morphologies on microstructure and properties of textured K0.5Na0.5NbO3 ceramics by RTGG method

Lead free textured K
_0.5
Na
_0.5
NbO
₃
piezoelectric ceramics have been prepared by reactive-templated grain growth method by using NaNbO
₃
with different morphologies as templates. The NaNbO
₃
template particles with different edge length (10-20 μm) and thickness (0.5-2.5 μm) was synthesized through controlling Bi
_1.5
Na
_x-1.5
Nb
_x
O
_3x+3
precursor's layer numbers x from 2 to 6 by two-step molten salt methods. The crystalline phases and microstructure of textured K
_0.5
Na
_0.5
NbO
₃
were characterized by X-ray diffraction and scanning electron microscopy, respectively. It shows that all the K
_0.5
Na
_0.5
NbO
₃
ceramics are orthorhombic perovskite structure with {0 0 1} orientation. By using the template particles with a ratio of edge length to thickness (l/h) =~10, the textured ceramics with optimized piezoelectric properties was prepared. The results indicate that the enhanced properties of textured ceramics are concerned with the template morphology.